Belt training idler



Feb. 14, 1967 H. HARTZELL, JR 3,303,924

BELT TRAINING IDLER Filed Sept. 29, 1965 2 Sheets-Sheet 1 25 23/INVENTOR.

HAPPY F. HAETZELL.

ilk S 6M Hg 3 1967 H. F. HARTZELL, JR 3,303,924

BELT TRAINING IDLER Filed Sept. 29, 1965 2 Sheets-Sheet 2 INVENTOR.

HAPPY E HAETZELL FIG. 5 gQ W his o4iZa rm;

United States Patent 3,303,924 BELT TRAINING IDLER Harry F. Hartzell,3L, Allison Park, Pa., assignor to Koppers Company, Inc, a corporationof Delaware F iied Sept. 29, 1965, Ser. No. 491,098 11 Claims. (Cl.198-202) This invention relates to material conveying apparatus and moreparticularly to apparatus for training a material conveying belt in aproper direction.

For a number of reasons, flexible conveyor belts which are relativelylong often tend to move laterally and become misaligned, so that theyrun on either one side or the other of a desired aligned centrallongitudinal axial position on the carrying idlers. Such misalignment ofthe carrying flight, and the return flight as well, may be due to:improper alignment of the idlers with the head and tail pulleys; unevensettling of the idler supporting structures; improper belt construction;improper splices in the belt; uneven loading of the belt; and the like.

In order to correct such misalignment, it is standard practice toprovide a relatively long belt conveyor with mechanical devices ortraining idlers which function to detect such misalignment and exert acorrecting force against the belt whereby the belt is returned to acentered position on the idlers.

The present invention is unlike many devices that are available becauseit effectively trains a conveyor belt whether or not it is movingforward or backward. An embodiment of the invention includes a framewhich is pivotally mounted in a fixed bearing for movement about an axisthat is substantially normal to the belt. On the frame there are aplurality of idler rollers which are mounted for rotation about axeswhich, preferably, lie in a single vertical plane. Spaced apart firstand second guide arms are pivotally mounted at the ends of the frame, oneach side of the belt, and on each guide arm is mounted a guide rollerwhich is rotatable about an axis that is generally normal to the guidearm.

Adjacent each set of guide arms and mounted to the frame is a cam platewhich is slidable in a direction substantially parallel to thelongitudinal axis of the belt. The cam plate has well rounded corners ateach end which engage and coact with cam shaped lugs on each guide arm.Stops are provided to restrict the pivotal movement of the guide armswithin desired limits.

On each cam plate there are a pair of spaced apart lugs which coactrespectively with the teeth of a pair of sprocket wheels mounted on theouter ends of the idler rollers by means of one-way or over-runningclutches. When the belt commences to move in one direction, the sprocketteeth of one of the wheels on each side of the belt, coact with one ofthe lugs to slide the cam plates into locking coacting relation with oneof the guide arms on each side of the belt. The coacting guide arms arethen fixed relative to the frame and urge the frame to pivot about thehearing when the misaligned belt engages one of the guide rollersmounted on the guide arms.

For a further understanding of the present invention and for furtheradvantages and features thereof, reference may be made to the followingdescription taken in conjunction with the accompanying drawings whichshow, for the purpose of exemplification, a preferred embodiment of theinvention.

In the drawings:

FIG. 1 is a schematic plan view of a belt training idler embodying theinvention;

FIG. 2 is an end view of the embodiment of FIG. 1

looking in the direction of the arrow A;

FIG. 3 is a view along line HI-III of FIG. 2; FIG. 4 is a view alongline IVIV of FIG. 2; and

"ice

FIG. 5 is a sectional view along line VV of FIG. 4.

FIG. 1 illustrates a portion of a material conveyor belt 11 supported ona belt training idler 13 which includes a plurality of idler rollers 15;there being shown for the purpose of the embodiment three idler rollers15a, 15b, 150. Both ends of the middle rollers 15c and the inner ends ofthe outer rollers 15a, 15b are journally mounted to supports 17, 19fixed to a troughed support frame 21, which is pivotally mounted, as at23, preferably in a central location, to a suitable fixable base member25. The base member 25 extends generally transversely of the conveyorbelt 11 and may be conveniently fastened in any suitable manner to othersupporting structure.

The outer end portions of the support frame 21 carry pivot arm supportplates 27, 29, disposed transversely to the frame 21, and pairs of guidearms 31a, 31b, and 33a, 3317 which are independently pivotally mountedby bolts 32 in spaced apart relation at the ends of the support plates27, 29. On each guide arm 31a, 31b, 33a, and 33b, adjacent the free endthereof, is mounted a single upstanding guide roller, such as rollers35a, 35b, 37a, and 37b.

The outer idler rollers 15a, 15b are inclined upwardly in theconventional manner, and are generally parallel to the upwardly inclinedportions of the troughed frame 21, as shown in FIG. 2. The upper outerend of each idler roller 15a, 15b is provided with a hollow shaft 39, 41which is secured to the rollers in a conventional manner for rotationtherewith. The rollers 15a, 15b are journally mounted on a spindle shaft43, 45 which extends through the hollow shafts 39, 41 and which issuitably joumaled at the lower inner end in the supports 17, 19 and atthe outer upper end in outer support brackets 47, 49. The outer supportbrackets 47, 49 are conveniently secured to the frame 21 by bolts, capscrews, or by means of any other suitable type of fastener.

The hollow shafts 39, 41, being fixed to the rollers 15a, 15brespectively, rotate at the same angular velocity as the idler rollers.Two sprocket wheels 51, 53, and 55, 57, are mounted on the hollow shafts39 and 41 respectively, and the hub of each of the sprocket wheels 51,53 and 55, 57 is fitted with an over-running or one-way clutch ofconventional type.

The over-running clutch which is marketed under the trademark Formsprag,has been found to be suitable. Of course, other apparatus may be foundwhich are suitable for moving the cam plates in the manner describedherein, in quick response to changes in direction of the movement of thebelt 11.

Each of the sprocket wheels 51 and 55 transmits torque from itsrespective hollow shaft 39 and 41 through one of the over-runningclutches as the rollers 15a and 15b rotate in the direction indicated bythe solid directional arrow A in FIG. 1. Likewise, each of the sprocketwheels 53 and 57 transmits torque from its respective hollow shaft 39and 41 through the other set of the over-running clutches when therollers 15a and 15b rotate reversibly, that is in the direction of thedotted directional arrow B of FIG. 1.

The teeth 5911 on the periphery of the sprocket wheels 53, 51 and teeth59b on the periphery of the sprocket wheels 57, 55 engage with lugs 61and 63 respectively on cam plates 65, 67 which are slidably supportedand mounted on the frame 21 adjacent the outer support plates 27, 29.The cam plates 65, 67 are mounted in such a manner that, when urged by aforce acting on the lugs 61 or 63, they are free to slide in a directionsubstantially parallel to the longitudinal axis of the conveyor belt 11.

Preferably, each cam plate 65, 67 is provided with a tongue 69 whichmates with a groove in the support frame 21, as may be seen in FIG. 5,and the linear travel of the cam plates 65, 67 is limited, preferably,by stop lugs 71a,

3 71b located on the underside of the cam plates 65, 67 which engage thesides of the support frame 21. In FIGS. 3 and 4, the belt 11 is movingin the direction of the arrow A and the cam plate 65 is shown in thefarthest left position; the stop lug 71a engaging the right hand side ofthe frame 21.

The periphery of each slidable cam plate 65, 67 is provided with a pairof generously rounded corners 73a, 73b, as indicated in FIG. 4, whichserve as cams to engage and actuate cam follower lugs 75a, 75b, 77a, and77b on the guide arms 31a, 31b, 33a, and 33]; respectively. Each camfollower lug 75a, 75b, 77a, 77b is provided with a flat surface 79 whichengages a vertical stop 81 that is fixed to the support plates 27, 29and that limits the pivotal movement of the guide arms 31a, 31b, 33a,and 33b.

In operation, the conveyor belt 11 is reversible and moves forwardly inthe direction of the arrow A, and reversibly in the direction of thearrow B. Initially, it is assumed that the belt 11 is travelingforwardly in the direction of the arrow A, and is substantially alignedon the idler rollers 15.

When the belt first commences to move in the direction of the arrow A,the hollow shafts 39, 41, which are secured to the rollers 15a, 15b,rotate. The sprocket wheels 51, 55 rotate also because of the action ofthe over-running clutches mounted in the hubs of the sprocket wheels,whereby the teeth 59a on sprocket Wheels 51, 55 engage the lug 61 andurge the plates 65, on both sides of the belt, towards the left, asviewed in FIG. 3; that is to say, the plate 65 moves in a directionopposite to the direction of movement of the belt 11.

As the cam plate 65 moves toward the left, as seen in FIG. 4, thecam-like corner 73b engages the cam follower lug 75b, of the rollersupporting guide arm 31b, and the arm 31b, then rotates about its pivotaxis in bolts 32 until the straight edge 79 engages the vertical stoplug 81. It will be understood by those skilled in the art, of course,that the cam plate 65 on the other side of the belt (see FIG. 1) alsomoves toward the left, under the influence of the sprocket wheel 57, andengages the cam follower lug 77b of the guide arm 33b. In thissituation, both of the guide arms 31b, 33b are fixed and cannot pivotfurther, and the rollers 35b, 37!), mounted on the guide arms, are fixedin position relative to the frame 21 and the lateral edges of the belt11.

Although the guide arms 31b, 33b are fixed, the other roller supportingguide arms 31a, 33a, are free to pivot about their respective axes inbolts 32 and are not restrained except that the amount of pivoting islimited purposely by the vertical stop lugs 81 and a pointed projection83 on each guide arm which is engageable with the stop lug 81.

It should be apparent then, that the vertical rollers 35b, 37b and theguide arms 31b, 33b are operative to realign the conveyor belt wheneverthe same becomes misaligned and engages either rollers 35b or 37b. Theothr rollers 35a, 37a are now inoperative and are freely pivotablewithin the limits mentioned previously.

FIG. 1 also illustrates the belt 11 in a typical misaligned position,shown by the dotted outlined form; the belt having moved laterallytoward the upstanding guide rollers 35a, 35b. Actually, the longitudinaledge 85 of the belt 11, in the lower portion of FIG. 1, engages thefixed rollers 35b and the belt 11 then exerts a lateral force on theroller and guide arm 31b, which urges the entire idler roller assemblyto pivot in a counterclockwise direction about the central pivot 23. Thecounterclockwise pivotal motion is suggested by the directional arrow Cin FIG. 1. The idler assembly pivots in the direction of the arrow Cuntil the transverse axis 87 of the idler rollers 15 assumes a biasedposition, indicated generally at 87a in FIG. 1. In this biased position,the idler rollers 15 exert a force on the moving belt 11, in a mannerknown to those skilled in the art, which urges the belt laterally awayfrom the roller 35b and toward its initial centrally aligned position.As is known, when the belt moves laterally under the influence of thiscorrective force, the idler roller assembly pivots oppositely, or in thedirection of the arrow D, and also returns to its initial transverseposition.

In like manner, should the conveyor belt 11 move laterally intoengagement with the other fixed guide rollers 37b (upwardly, as viewedin FIG. 1), then the entire idler roller assembly will pivot clockwiseabout the axis of the bearing 23, in the direction of the arrow D, andthe idler rollers 15 will again exert a corrective force on the belt 11urging it back toward the central aligned position, as explainedpreviously.

Now, if it be assumed that the conveyor belt 11, after moving in thedirection of the arrow A, has been stopped and then commences to move inthe direction of the arrow B, the sprocket wheels 51, 55, acting throughthe other set of over-running clutches, immediately rotate in acounterclockwise direction, as viewed in FIG. 3. The teeth 59b onsprocket wheels 51, 55, being in contact with the lugs 63, immediatelymove the cam plates toward the right, as viewed in FIGS. 1 and 4. Whenthe cam plates 65 move toward the right, the cam-like corners 73a engageand coact with the cam follower lugs 75a, 77a of the roller supportingguide arms 31a, 33a respectively, whereby the guide arms 31a, 33a andthe rollers 35a, 37a become fixed relative to the support frame 21 andthe edges of the belt 11.

Thereafter, should the belt 11 while traveling in the direction of thearrow B, become misaligned and move laterally to bring the edge intoengagement with either the roller 35a or roller 37a, then theinteraction of the belt edge with the roller 35a or 37:: would causepivoting movement of the roller assembly in the direction of the arrowsD or C, as the case may be. And so, as explained previously, acorrective force acting between the belt 11 and the rollers 15 urges thebelt laterally toward its initial centrally aligned position.

In accordance with the present invention, pivotally mounted guide armsand belt engaging rollers supported thereon, on opposite sides of theconveyor belt, are automatically fixed relative to the support frame ofthe belt idler apparatus immediately the belt moves in one direc tion,and another pair of opposite guide arms and rollers are automaticallyfixed relative to the idler supporting frame immediately the beltreverses and moves in the op posite direction.

That the positioning of the respective opposite pairs of guide rollersoccurs automatically, whether the conveyor belt is moving forward orbackward, is significant in main. taining a reversible conveyor belt ina substantially cen= trally aligned position.

While the embodiment illustrated discloses a troughed frame andsupporting idler rollers, it will be understood by those skilled in theart that the invention is not so limited but is applicable to pivotedidlers supporting a flat return flight, a flat carrying flight, and thelike.

A significant feature of the present invention is the automatic fixingof an opposed pair of guide arms and the edge engaging rollers mountedthereon by means of the slidable cam plates which also disengagessimultaneously the other opposed pair of guide arms and renders themfreely pivotable, within preselected limits, and inoperative. Theoperative rollers on the fixed guide arms are automatically disposed ina position relative to the frame which is directionally opposite to thedirection of movement of the belt whereby when the edge of themisaligned belt engages one of the operative rollers a corrective forcecouple acting about the pivot axis of the frame urges the frame to pivotto a biased position relative to the axis of the belt.

Although the foregoing describes the invention with a certain degree ofparticularity, it is understood that the present disclosure has beenmade only by way of an example and that various modifications andchanges may be resorted to without departing from the spirit and scopeof the invention as hereinafter claimed.

What is claimed is:

1. A training idler for use with a material conveyor belt comprising:

(a) a frame pivotal about an axis substantially normal to said belt;

(b) an idler roller rotatably supported on said frame for alignablysupporting said belt;

(c) a guide arm pivotally mounted to said frame adjacent each endthereof on opposite sides of said belt;

(d) a guide roller rotatably mounted on each guide arm end portion;

(e) guide arm fixing members slidably mounted on said frame;

(f) means automatically operable in response to the rotation of saididler roller to move said guide arm fixing members in the directionopposite the movement of said belt and into fixable engagement with saidguide arms; and

g) means to fix said guide arms so that the rollers mounted thereon aredisposed in a position relative to said frame that is opposite indirection to the direction of movement of said belt, whereby when saidbelt becomes misaligned and one edge thereof engages one of said fixedrollers, said frame and the idler roller mounted thereon are pivotedinto a biased relation to said belt and said idler roller then exerts aforce on said belt which urges said misaligned belt into alignment.

2. A training idler for a reversible material belt conveyor comprising:

(a) a frame pivotal about an axis substantially normal to a belt movingin a first direction;

(b) a plurality of idler rollers rotatably supported on said frame foralignably supporting said belt;

() spaced apart first and second guide arms pivotally mounted to saidframe adjacent each end portion thereof on opposite sides of said belt;

(d) a guide roller rotatably mounted on each guide arm end portion;

(e) guide arm actuating members mounted slidably on said frame formovement substantially parallel to the axis of said belt;

(f) means automatically operable in response to the rotation of saididler roller to move said guide arm actuating members in the directionopposite said first direction and into engagement with a first one ofsaid guide arms on each side of said belt whereby said engaged guidearms pivot;

(g) means to fix the thus engaged first guide arms and the rollersmounted thereon in position relative to said frame whereby when saidbelt becomes misaligned and one edge thereof engages one of said firstfixed rollers, said frame and said idler rollers are pivoted into abiased position and said idler rollers exert a force on said belt whichurges said misaligned belt into alignment;

(h) means to move said guide arm actuating members in said firstdirection when said belt is moving in a second direction opposite tosaid first direction, and into engagement with a second one of saidguide arms on each side of said belt whereby said second guide armspivot; and

(i) means to fix the thus engaged second guide arms and the rollersmounted thereon in position relative to said frame whereby when saidbelt becomes misaligned and one edge thereof engages one of said secondfixed rollers, said frame and said idler rollers are pivoted into abiased position and said idler rollers exert a force on said belt whichurges said misaligned belt into alignment.

3. A training idler for a reversible conveyor belt comprising:

(a) a frame pivotable about an axis substantially normal to said belt;

(b) an idler roller rotatably mounted on said frame for supporting saidbelt in a normally aligned position transverse the axis of said roller;

(c) guide arms pivotally mounted on said frame on each side of said beltand supporting belt edge engaging means adjacent the ends of said arms;and

(d) means automatically operable in response to the rotation of saididler roller and slidable on said frame for coacting with a guide arm oneach side of said belt and fixing the edge engaging means mountedthereon each in a position relative to said frame that is opposite indirection to the direction of movement of said belt, whereby as saidmoving belt becomes misaligned and one edge thereof engages one of thefixed edge engaging means, said frame pivots about said normal axis andsaid idler roller is biased with respect to said belt and exerts analignment corrective force on said belt tending to urge said belt intosaid normally aligned position.

4. A belt training idler as set forth in claim 3 further characterizedin that:

(a) the rollers supported by said guide arms are maintained at the samelevel when contacting the edge of said belt irrespective of thedirection of movement of said belt.

5. A training idler as defined in claim 3 further characterized in that:

(a) the rotational axis of the rollers supported by said guide arms aresubstantially normal to the adjacent longitudinal edge of said belt.

6. The invention set forth in claim 3 further characterized in that:

(a) the guide arms on each side of said belt are pivotal about axeswhich are substantially parallel and perpendicular to the belt.

7. The invention set forth in claim 3 further characterized in that:

(a) the guide arms on both sides of the belt are individually pivotallymounted and alternately operative when the moving belt reverses itsdirection of movement.

8. A training idler for use with a conveyor belt adapted to travel infirst and second opposite directions comprismg:

(a) a bar disposed transversely of said belt and mounted for pivotalmovement about an axis sub stantially normal to said belt;

(b) roll means rotatably mounted on said bar for alignably supportingsaid belt and relative to which said belt may become misaligned;

(c) first and second spaced apart guide arms individually pivotallymounted to said bar on each side of said belt;

(d) means mounted on said guide arms engageable with the edge of saidbelt;

(e) cam plates slidably mounted to said bar; and

(f) clutch actuated sprocket wheel means mounted on said roll means andengageable with said cam plates as said belt moves in said first andsecond directions, said cam plates moving oppositely to the movement ofsaid belt into engagement with a guide arm on each side of said belt andfixing said belt edge engaging means in relation to said transverse barwhereby as said belt becomes misaligned with respect to said roll meansand contacts a fixed edge engaging means, said roll means is moved to abiased position with respect to said belt and exerts a force on saidbelt urging the same toward an aligned position relative to said rollmeans.

9. In a belt training idler for supporting a conveyor belt including atransversely disposed frame pivotally mounted 7 I for movement about anaxis substantially normal to a portion of the belt and roller meansrotatably mounted on said frame for supporting said belt, theimprovement comprising:

(a) a plurality of guide arms independently pivotally mounted to saidframe on each side of said belt;

(b) means mounted on each guide arm for engagement with the edge of saidbelt;

() means slidably mounted on said frame for engagement with and fixingat least one guide arm on each side of said belt; and

(d) sprocket wheel means actuatable by said roller means engaging saidframe mounted slidable means whereby, as said belt moves in a givendirection, said frame mounted slidable means moves in the oppositedirection and fixedly engages one of said guide arms on each side ofsaid belt relative to said frame, the edge engaging means mounted onsaid fixed guide arms being disposed relative to said frame in adirection opposite the given direction of movement of said belt, wherebyas said belt becomes misaligned with respect to said roller means andengages a fixed edge engaging means, said frame is pivoted into biasedrelation with respect to said belt and said roller means exerts a forceon said belt urging the same toward an aligned position relative to saidroller means.

10. A training device for maintaining a travelling belt in a preselectedline of travel comprising:

(a) a roller for supporting said belt extending generally transverselyof said belt and journally mounted in means adapted for rotation aboutan axis perpendicular to said belt;

(b) guide means displaced from said roller adapted to engage and coactwith an edge of said belt;

(c) means automatically operable in response to the rotation of saididler roller and laterally movable in a direction substantially oppositeand parallel to the direction of travel of said belt and engageable withsaid guide means whereby the same is fixed relative to said rollermounting means; and

(d) means connecting said guide means and said roller mounting means forapplying to said roller a force derived from the force exerted by saidbelt against said guide means when the same travels in a line differentfrom said preselected line whereby said roller is biased with respect tosaid belt line of travel and said biased roller applies a correctiveforce to said belt and the same returns to its preselected line oftravel.

11. A training device for maintaining a moving belt in a preselectedline of travel comprising:

(a) roller means extending generally transversely of said belt androtatably mounted in means adapted for rotation about an axissubstantially normal to said belt;

(b) guide means displaced from the axis of said roller adapted to engageand coact with an edge of said belt;

(c) linkage connecting said guide means and said roller supporting meansadapted for applying a force to said roller derived from the forceexerted on said guide means when the same is contacted by said belt asit travels in a line different from said preselected line of travel andsaid roller is biased with respect to said belt and said roller appliesto said belt a corrective force urging said belt to said preselectedline of travel; and

(d) means operable in response to the rotation of said idler roller andautomatically movable translationally in a direction opposite thedirection of movement of said belt and engageable with said guide meansto fix the same in a location with respect to the axis of said roller onthe side thereof opposite the direction of travel of said belt.

References Cited by the Examiner UNITED STATES PATENTS 2,821,291 1/1958Schott 198-202 2,892,534 6/1959 Ogden 198202 3,066,547 12/1962 Evans etal 198202 X 3,246,736 4/1966 Lo Presti 198202 EVON C. BLUNK, PrimaryExaminer.

M. L. AJEMAN, Assistant Examiner.

1. A TRAINING IDLER FOR USE WITH A MATERIAL CONVEYOR BELT COMPRISING:(A) A FRAME PIVOTAL ABOUT AN AXIS SUBSTANTIALLY NORMAL TO SAID BELT; (B)AN IDLER ROLLER ROTATABLY SUPPORTED ON SAID FRAME FOR ALIGNABLYSUPPORTING SAID BELT; (C) A GUIDE ARM PIVOTALLY MOUNTED TO SAID FRAMEADJACENT EACH END THEREOF ON OPPOSITE SIDES OF SAID BELT; (D) A GUIDEROLLER ROTATABLY MOUNTED ON EACH GUIDE ARM END PORTION; (E) GUIDE ARMFIXING MEMBERS SLIDABLY MOUNTED ON SAID FRAME; (F) MEANS AUTOMATICALLYOPERABLE IN RESPONSE TO THE ROTATION OF SAID IDLER ROLLER TO MOVE SAIDGUIDE ARM FIXING MEMBERS IN THE DIRECTION OPPOSITE THE MOVEMENT OF SAIDBELT AND INTO FIXABLE ENGAGEMENT WITH SAID GUIDE ARMS; AND (G) MEANS TOFIX SAID GUIDE ARMS SO THAT THE ROLLERS MOUNTED THEREON ARE DISPOSED INA POSITION RELATIVE TO SAID FRAME THAT IS OPPOSITE IN DIRECTION TO THEDIRECTION OF MOVEMENT OF SAID BELT, WHEREBY WHEN SAID BELT BECOMESMISALIGNED AND ONE EDGE THEREOF ENGAGES ONE OF SAID FIXED ROLLERS, SAIDFRAME AND THE IDLER ROLLER MOUNTED THEREON ARE PIVOTED INTO A BIASEDRELATION TO SAID BELT AND SAID IDLER ROLLER THEN EXERTS A FORCE ON SAIDBELT WHICH URGES SAID MISALIGNED BELT INTO ALIGNMENT.